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Diffstat (limited to 'src/libid3tag/frame.c')
-rw-r--r--src/libid3tag/frame.c626
1 files changed, 626 insertions, 0 deletions
diff --git a/src/libid3tag/frame.c b/src/libid3tag/frame.c
new file mode 100644
index 00000000..aafd54e2
--- /dev/null
+++ b/src/libid3tag/frame.c
@@ -0,0 +1,626 @@
+/*
+ * libid3tag - ID3 tag manipulation library
+ * Copyright (C) 2000-2003 Underbit Technologies, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * $Id: frame.c,v 1.1 2003/08/14 03:57:13 shank Exp $
+ */
+
+# ifdef HAVE_CONFIG_H
+# include "config.h"
+# endif
+
+# include "global.h"
+
+# include <stdlib.h>
+# include <string.h>
+
+# ifdef HAVE_ASSERT_H
+# include <assert.h>
+# endif
+
+# include "id3tag.h"
+# include "frame.h"
+# include "frametype.h"
+# include "compat.h"
+# include "field.h"
+# include "render.h"
+# include "parse.h"
+# include "util.h"
+
+static
+int valid_idchar(char c)
+{
+ return (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9');
+}
+
+/*
+ * NAME: frame->validid()
+ * DESCRIPTION: return true if the parameter string is a legal frame ID
+ */
+int id3_frame_validid(char const *id)
+{
+ return id &&
+ valid_idchar(id[0]) &&
+ valid_idchar(id[1]) &&
+ valid_idchar(id[2]) &&
+ valid_idchar(id[3]);
+}
+
+/*
+ * NAME: frame->new()
+ * DESCRIPTION: allocate and return a new frame
+ */
+struct id3_frame *id3_frame_new(char const *id)
+{
+ struct id3_frametype const *frametype;
+ struct id3_frame *frame;
+ unsigned int i;
+
+ if (!id3_frame_validid(id))
+ return 0;
+
+ frametype = id3_frametype_lookup(id, 4);
+ if (frametype == 0) {
+ switch (id[0]) {
+ case 'T':
+ frametype = &id3_frametype_text;
+ break;
+
+ case 'W':
+ frametype = &id3_frametype_url;
+ break;
+
+ case 'X':
+ case 'Y':
+ case 'Z':
+ frametype = &id3_frametype_experimental;
+ break;
+
+ default:
+ frametype = &id3_frametype_unknown;
+ if (id3_compat_lookup(id, 4))
+ frametype = &id3_frametype_obsolete;
+ break;
+ }
+ }
+
+ frame = malloc(sizeof(*frame) + frametype->nfields * sizeof(*frame->fields));
+ if (frame) {
+ frame->id[0] = id[0];
+ frame->id[1] = id[1];
+ frame->id[2] = id[2];
+ frame->id[3] = id[3];
+ frame->id[4] = 0;
+
+ frame->description = frametype->description;
+ frame->refcount = 0;
+ frame->flags = frametype->defaultflags;
+ frame->group_id = 0;
+ frame->encryption_method = 0;
+ frame->encoded = 0;
+ frame->encoded_length = 0;
+ frame->decoded_length = 0;
+ frame->nfields = frametype->nfields;
+ frame->fields = (union id3_field *) &frame[1];
+
+ for (i = 0; i < frame->nfields; ++i)
+ id3_field_init(&frame->fields[i], frametype->fields[i]);
+ }
+
+ return frame;
+}
+
+void id3_frame_delete(struct id3_frame *frame)
+{
+ assert(frame);
+
+ if (frame->refcount == 0) {
+ unsigned int i;
+
+ for (i = 0; i < frame->nfields; ++i)
+ id3_field_finish(&frame->fields[i]);
+
+ if (frame->encoded)
+ free(frame->encoded);
+
+ free(frame);
+ }
+}
+
+/*
+ * NAME: frame->addref()
+ * DESCRIPTION: add an external reference to a frame
+ */
+void id3_frame_addref(struct id3_frame *frame)
+{
+ assert(frame);
+
+ ++frame->refcount;
+}
+
+/*
+ * NAME: frame->delref()
+ * DESCRIPTION: remove an external reference to a frame
+ */
+void id3_frame_delref(struct id3_frame *frame)
+{
+ assert(frame && frame->refcount > 0);
+
+ --frame->refcount;
+}
+
+/*
+ * NAME: frame->field()
+ * DESCRIPTION: return a pointer to a field in a frame
+ */
+union id3_field *id3_frame_field(struct id3_frame const *frame,
+ unsigned int index)
+{
+ assert(frame);
+
+ return (index < frame->nfields) ? &frame->fields[index] : 0;
+}
+
+static
+struct id3_frame *obsolete(char const *id, id3_byte_t const *data,
+ id3_length_t length)
+{
+ struct id3_frame *frame;
+
+ frame = id3_frame_new(ID3_FRAME_OBSOLETE);
+ if (frame) {
+ if (id3_field_setframeid(&frame->fields[0], id) == -1 ||
+ id3_field_setbinarydata(&frame->fields[1], data, length) == -1)
+ goto fail;
+ }
+
+ if (0) {
+ fail:
+ if (frame) {
+ id3_frame_delete(frame);
+ frame = 0;
+ }
+ }
+
+ return frame;
+}
+
+static
+struct id3_frame *unparseable(char const *id, id3_byte_t const **ptr,
+ id3_length_t length, int flags,
+ int group_id, int encryption_method,
+ id3_length_t decoded_length)
+{
+ struct id3_frame *frame = 0;
+ id3_byte_t *mem;
+
+ mem = malloc(length ? length : 1);
+ if (mem == 0)
+ goto fail;
+
+ frame = id3_frame_new(id);
+ if (frame == 0)
+ free(mem);
+ else {
+ memcpy(mem, *ptr, length);
+
+ frame->flags = flags;
+ frame->group_id = group_id;
+ frame->encryption_method = encryption_method;
+ frame->encoded = mem;
+ frame->encoded_length = length;
+ frame->decoded_length = decoded_length;
+ }
+
+ if (0) {
+ fail:
+ ;
+ }
+
+ *ptr += length;
+
+ return frame;
+}
+
+static
+int parse_data(struct id3_frame *frame,
+ id3_byte_t const *data, id3_length_t length)
+{
+ enum id3_field_textencoding encoding;
+ id3_byte_t const *end;
+ unsigned int i;
+
+ encoding = ID3_FIELD_TEXTENCODING_ISO_8859_1;
+
+ end = data + length;
+
+ for (i = 0; i < frame->nfields; ++i) {
+ if (id3_field_parse(&frame->fields[i], &data, end - data, &encoding) == -1)
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * NAME: frame->parse()
+ * DESCRIPTION: parse raw frame data according to the specified ID3 tag version
+ */
+struct id3_frame *id3_frame_parse(id3_byte_t const **ptr, id3_length_t length,
+ unsigned int version)
+{
+ struct id3_frame *frame = 0;
+ id3_byte_t const *id, *end, *data;
+ id3_length_t size, decoded_length = 0;
+ int flags = 0, group_id = 0, encryption_method = 0;
+ struct id3_compat const *compat = 0;
+ id3_byte_t *mem = 0;
+ char xid[4];
+
+ id = *ptr;
+ end = *ptr + length;
+
+ if (ID3_TAG_VERSION_MAJOR(version) < 4) {
+ switch (ID3_TAG_VERSION_MAJOR(version)) {
+ case 2:
+ if (length < 6)
+ goto fail;
+
+ compat = id3_compat_lookup(id, 3);
+
+ *ptr += 3;
+ size = id3_parse_uint(ptr, 3);
+
+ if (size > end - *ptr)
+ goto fail;
+
+ end = *ptr + size;
+
+ break;
+
+ case 3:
+ if (length < 10)
+ goto fail;
+
+ compat = id3_compat_lookup(id, 4);
+
+ *ptr += 4;
+ size = id3_parse_uint(ptr, 4);
+ flags = id3_parse_uint(ptr, 2);
+
+ if (size > end - *ptr)
+ goto fail;
+
+ end = *ptr + size;
+
+ if (flags & (ID3_FRAME_FLAG_FORMATFLAGS & ~0x00e0)) {
+ frame = unparseable(id, ptr, end - *ptr, 0, 0, 0, 0);
+ goto done;
+ }
+
+ flags =
+ ((flags >> 1) & ID3_FRAME_FLAG_STATUSFLAGS) |
+ ((flags >> 4) & (ID3_FRAME_FLAG_COMPRESSION |
+ ID3_FRAME_FLAG_ENCRYPTION)) |
+ ((flags << 1) & ID3_FRAME_FLAG_GROUPINGIDENTITY);
+
+ if (flags & ID3_FRAME_FLAG_COMPRESSION) {
+ if (end - *ptr < 4)
+ goto fail;
+
+ decoded_length = id3_parse_uint(ptr, 4);
+ }
+
+ if (flags & ID3_FRAME_FLAG_ENCRYPTION) {
+ if (end - *ptr < 1)
+ goto fail;
+
+ encryption_method = id3_parse_uint(ptr, 1);
+ }
+
+ if (flags & ID3_FRAME_FLAG_GROUPINGIDENTITY) {
+ if (end - *ptr < 1)
+ goto fail;
+
+ group_id = id3_parse_uint(ptr, 1);
+ }
+
+ break;
+
+ default:
+ goto fail;
+ }
+
+ /* canonicalize frame ID for ID3v2.4 */
+
+ if (compat && compat->equiv)
+ id = compat->equiv;
+ else if (ID3_TAG_VERSION_MAJOR(version) == 2) {
+ xid[0] = 'Y';
+ xid[1] = id[0];
+ xid[2] = id[1];
+ xid[3] = id[2];
+
+ id = xid;
+
+ flags |=
+ ID3_FRAME_FLAG_TAGALTERPRESERVATION |
+ ID3_FRAME_FLAG_FILEALTERPRESERVATION;
+ }
+ }
+ else { /* ID3v2.4 */
+ if (length < 10)
+ goto fail;
+
+ *ptr += 4;
+ size = id3_parse_syncsafe(ptr, 4);
+ flags = id3_parse_uint(ptr, 2);
+
+ if (size > end - *ptr)
+ goto fail;
+
+ end = *ptr + size;
+
+ if (flags & (ID3_FRAME_FLAG_FORMATFLAGS & ~ID3_FRAME_FLAG_KNOWNFLAGS)) {
+ frame = unparseable(id, ptr, end - *ptr, flags, 0, 0, 0);
+ goto done;
+ }
+
+ if (flags & ID3_FRAME_FLAG_GROUPINGIDENTITY) {
+ if (end - *ptr < 1)
+ goto fail;
+
+ group_id = id3_parse_uint(ptr, 1);
+ }
+
+ if ((flags & ID3_FRAME_FLAG_COMPRESSION) &&
+ !(flags & ID3_FRAME_FLAG_DATALENGTHINDICATOR))
+ goto fail;
+
+ if (flags & ID3_FRAME_FLAG_ENCRYPTION) {
+ if (end - *ptr < 1)
+ goto fail;
+
+ encryption_method = id3_parse_uint(ptr, 1);
+ }
+
+ if (flags & ID3_FRAME_FLAG_DATALENGTHINDICATOR) {
+ if (end - *ptr < 4)
+ goto fail;
+
+ decoded_length = id3_parse_syncsafe(ptr, 4);
+ }
+ }
+
+ data = *ptr;
+ *ptr = end;
+
+ /* undo frame encodings */
+
+ if ((flags & ID3_FRAME_FLAG_UNSYNCHRONISATION) && end - data > 0) {
+ mem = malloc(end - data);
+ if (mem == 0)
+ goto fail;
+
+ memcpy(mem, data, end - data);
+
+ end = mem + id3_util_deunsynchronise(mem, end - data);
+ data = mem;
+ }
+
+ if (flags & ID3_FRAME_FLAG_ENCRYPTION) {
+ frame = unparseable(id, &data, end - data, flags,
+ group_id, encryption_method, decoded_length);
+ goto done;
+ }
+
+ if (flags & ID3_FRAME_FLAG_COMPRESSION) {
+ id3_byte_t *decomp;
+
+ decomp = id3_util_decompress(data, end - data, decoded_length);
+ if (decomp == 0)
+ goto fail;
+
+ if (mem)
+ free(mem);
+
+ data = mem = decomp;
+ end = data + decoded_length;
+ }
+
+ /* check for obsolescence */
+
+ if (compat && !compat->equiv) {
+ frame = obsolete(id, data, end - data);
+ goto done;
+ }
+
+ /* generate the internal frame structure */
+
+ frame = id3_frame_new(id);
+ if (frame) {
+ frame->flags = flags;
+ frame->group_id = group_id;
+
+ if (compat && compat->translate) {
+ if (compat->translate(frame, compat->id, data, end - data) == -1)
+ goto fail;
+ }
+ else {
+ if (parse_data(frame, data, end - data) == -1)
+ goto fail;
+ }
+ }
+
+ if (0) {
+ fail:
+ if (frame) {
+ id3_frame_delete(frame);
+ frame = 0;
+ }
+ }
+
+ done:
+ if (mem)
+ free(mem);
+
+ return frame;
+}
+
+static
+id3_length_t render_data(id3_byte_t **ptr,
+ union id3_field *fields, unsigned int length)
+{
+ id3_length_t size = 0;
+ enum id3_field_textencoding encoding;
+ unsigned int i;
+
+ encoding = ID3_FIELD_TEXTENCODING_ISO_8859_1;
+
+ for (i = 0; i < length; ++i)
+ size += id3_field_render(&fields[i], ptr, &encoding, i < length - 1);
+
+ return size;
+}
+
+/*
+ * NAME: frame->render()
+ * DESCRIPTION: render a single, complete frame
+ */
+id3_length_t id3_frame_render(struct id3_frame const *frame,
+ id3_byte_t **ptr, int options)
+{
+ id3_length_t size = 0, decoded_length, datalen;
+ id3_byte_t *size_ptr = 0, *flags_ptr = 0, *data = 0;
+ int flags;
+
+ assert(frame);
+
+ if ((frame->flags & ID3_FRAME_FLAG_TAGALTERPRESERVATION) ||
+ ((options & ID3_TAG_OPTION_FILEALTERED) &&
+ (frame->flags & ID3_FRAME_FLAG_FILEALTERPRESERVATION)))
+ return 0;
+
+ /* a frame must be at least 1 byte big, excluding the header */
+
+ decoded_length = render_data(0, frame->fields, frame->nfields);
+ if (decoded_length == 0 && frame->encoded == 0)
+ return 0;
+
+ /* header */
+
+ size += id3_render_immediate(ptr, frame->id, 4);
+
+ if (ptr)
+ size_ptr = *ptr;
+
+ size += id3_render_syncsafe(ptr, 0, 4);
+
+ if (ptr)
+ flags_ptr = *ptr;
+
+ flags = frame->flags;
+
+ size += id3_render_int(ptr, flags, 2);
+
+ if (flags & (ID3_FRAME_FLAG_FORMATFLAGS & ~ID3_FRAME_FLAG_KNOWNFLAGS)) {
+ size += id3_render_binary(ptr, frame->encoded, frame->encoded_length);
+ if (size_ptr)
+ id3_render_syncsafe(&size_ptr, size - 10, 4);
+
+ return size;
+ }
+
+ flags &= ID3_FRAME_FLAG_KNOWNFLAGS;
+
+ flags &= ~ID3_FRAME_FLAG_UNSYNCHRONISATION;
+ if (options & ID3_TAG_OPTION_UNSYNCHRONISATION)
+ flags |= ID3_FRAME_FLAG_UNSYNCHRONISATION;
+
+ if (!(flags & ID3_FRAME_FLAG_ENCRYPTION)) {
+ flags &= ~ID3_FRAME_FLAG_COMPRESSION;
+ if (options & ID3_TAG_OPTION_COMPRESSION)
+ flags |= ID3_FRAME_FLAG_COMPRESSION | ID3_FRAME_FLAG_DATALENGTHINDICATOR;
+ }
+
+ if (flags & ID3_FRAME_FLAG_GROUPINGIDENTITY)
+ size += id3_render_int(ptr, frame->group_id, 1);
+ if (flags & ID3_FRAME_FLAG_ENCRYPTION)
+ size += id3_render_int(ptr, frame->encryption_method, 1);
+ if (flags & ID3_FRAME_FLAG_DATALENGTHINDICATOR) {
+ if (flags & ID3_FRAME_FLAG_ENCRYPTION)
+ decoded_length = frame->decoded_length;
+ size += id3_render_syncsafe(ptr, decoded_length, 4);
+ }
+
+ if (ptr)
+ data = *ptr;
+
+ if (flags & ID3_FRAME_FLAG_ENCRYPTION)
+ datalen = id3_render_binary(ptr, frame->encoded, frame->encoded_length);
+ else {
+ if (ptr == 0)
+ datalen = decoded_length;
+ else {
+ datalen = render_data(ptr, frame->fields, frame->nfields);
+
+ if (flags & ID3_FRAME_FLAG_COMPRESSION) {
+ id3_byte_t *comp;
+ id3_length_t complen;
+
+ comp = id3_util_compress(data, datalen, &complen);
+ if (comp == 0)
+ flags &= ~ID3_FRAME_FLAG_COMPRESSION;
+ else {
+ *ptr = data;
+ datalen = id3_render_binary(ptr, comp, complen);
+
+ free(comp);
+ }
+ }
+ }
+ }
+
+ /* unsynchronisation */
+
+ if (flags & ID3_FRAME_FLAG_UNSYNCHRONISATION) {
+ if (data == 0)
+ datalen *= 2;
+ else {
+ id3_length_t newlen;
+
+ newlen = id3_util_unsynchronise(data, datalen);
+ if (newlen == datalen)
+ flags &= ~ID3_FRAME_FLAG_UNSYNCHRONISATION;
+ else {
+ *ptr += newlen - datalen;
+ datalen = newlen;
+ }
+ }
+ }
+
+ size += datalen;
+
+ /* patch size and flags */
+
+ if (size_ptr)
+ id3_render_syncsafe(&size_ptr, size - 10, 4);
+ if (flags_ptr)
+ id3_render_int(&flags_ptr, flags, 2);
+
+ return size;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-07 12:20:05 +0000